Pro-inflammatory cytokines and neurobehavioral symptoms in women with breast cancer. Abstract Survivors of breast cancer report debilitating behavioral symptoms, such as fatigue and neurocognitive dysfunction, which are evident in some individuals even at pre-treatment baseline. There is sufficient evidence from varied lines of research to propose that cancer-related neurobehavioral symptoms may be driven, at least in part, by activation of the pro-inflammatory cytokine network. Concentrations of specific pro-inflammatory cytokines (IL-6, TNF) and soluble receptors in serum obtained prior to treatment in breast cancer patients are significantly higher than levels found in healthy individuals and have prognostic value;however, these pre- treatment elevations have not yet been evaluated with respect to their association with either acute or chronic behavioral symptoms. Among survivors of breast cancer, elevated levels of circulating sIL-6R and IL-1ra have emerged as prominent biomarkers of persistent fatigue in cross-sectional studies of women several years post chemotherapy. No similar work has identified biomarkers of neurocognitive dysfunction in this patient population, and it is not known if the cytokine links with fatigue, or other behavioral symptoms, exist closer to the diagnosis period or evolve over time as "late effects". In this study, we will address this knowledge gap as we will evaluate this association prior to cancer treatment, and again following treatment completion. We will compare these associations in a minimum of 137 breast cancer patients relative to two comparison groups at pre-treatment, and longitudinally evaluate only the breast cancer group after treatment. Findings are expected to increase our knowledge about the possible biomarkers associated with neurobehavioral symptoms in breast cancer patients, for the purpose of better identifying and treating those at risk for such effects. PUBLIC HEALTH RELEVANCE: Findings are expected to increase knowledge about the possible biomarkers associated with neurobehavioral symptoms in breast cancer patients, for the purpose of better identifying and treating those at risk for such effects.